According to the Washington Post newspaper, Secretary of State John F. Kerry and senior officials from two dozen nations meeting here Tuesday declared that Syria’s cease-fire “is not dead ” but offered no ideas on how it can be preserved after heavy fighting, including the bombing of a humanitarian aid convoy, broke out again this week.

“The mood of the meeting is that nobody wants to give this thing up. It’s the only show in town,” British Foreign Secretary Boris Johnson said after an hour-long session that others described as “tense” and “dramatic.”

The United Nations and other relief agencies suspended all aid shipments across combat lines in the wake of the convoy bombing Monday. The deadly incident capped a rapid unraveling of week-old truce efforts brokered by the United States and Russia. The plan was intended to open routes to aid thousands of besieged Syrians, possibly spur greater military counterterrorism cooperation between Moscow and Washington, and create conditions for a resumption of negotiations on a long-term political solution to Syria’s civil war.